Factory pre-set at 1500 PSI adjustable from 1000 to 2000 PSI. Spring centered. 3/4in. inlet/outlet and 3/4in. work ports. For use with 5in. and larger cylinders and 20 gallon pumps. Up to 25 gallons per minute. Adjustable Release Pressure PSI 1,000-2,000, Inlet Port in. 3/4, Max. Flow GPM 25, Max. PSI 3,000, Working Port in. 3/4.